It is easy to fall in love with Guanacaste in February. Blue sky, dry roads, full restaurants, every rental booked. Then they buy, and their first October teaches them what the brochure left out.
Living in Guanacaste year-round is very doable, and green season has real rewards. But it also has a real price. This guide breaks that price into the four lines that matter: power, roads, humidity, and vacancy. By the end, you will know what each one costs, what you can control, and the exact steps to take before the rains arrive.
When Is the Guanacaste Rainy Season?
The Guanacaste rainy season runs from May through November, with the heaviest rain in September and October. December through March is the true dry season. Most green season days start sunny, and rain usually arrives as afternoon or evening storms rather than all-day downpours.
The numbers show how lopsided the year is. According to Costa Rica's official tourism board, only 4 percent of the region's annual rain falls from December to March, while May through August delivers about half of it. The same source notes a short break called the veranillo in July and August, when trade winds pick up and the rain eases.
Climate records compiled by Weather and Climate put October as the wettest month at about 354 mm of rain, compared with roughly 3 mm in February. That gap is why the same house can feel like two different properties depending on the month.
Green Season Costa Rica | The Pros and Cons for Year-Round Owners
Before we get into costs, here is the honest scorecard.
The pros
- Fewer crowds. Beaches, surf breaks, and restaurants are quieter, and the pace of town slows down.
- A greener, cooler coast. The dry forest turns lush, and the brutal heat of March and April softens.
- Real community. The people still here in October are your neighbors, not tourists. This is when relationships form.
- Better access to your own home. If you rent your property in peak months, green season is often when the calendar opens for owner use.
The cons
- Humidity that works on your house. Closets, cushions, leather, and electronics all feel it, especially when the home sits closed.
- Unpaved roads and rising rivers. Some routes turn slow, muddy, or briefly impassable after heavy storms.
- Occasional outages. Strong storms can knock out power and internet for hours in coastal communities.
- Softer rental demand. September is typically the slowest month for short-term rentals on this coast.
None of the cons are deal breakers. All of them cost money if you ignore them.
Cost 1: Power, and Why Your Bill Changes Shape
Here is the surprise. Green season is not always your highest electricity month. March and April are the hottest stretch in this part of the country, and air conditioning works hard. What changes in green season is why you run power: you are fighting moisture, not just heat.
For context, residential electricity in Costa Rica averaged about 85.9 colones per kWh (roughly $0.19) in December 2025, according to Global Petrol Prices data drawn from ARESEP. Prices are regulated, and the trend recently moved in owners' favor. ARESEP approved 2026 rate cuts ranging from 4.9 to 16.4 percent depending on the utility, with a 250 kWh household served by Coopeguanacaste saving about ¢1,779 per month.
The catch for larger homes is that residential tariffs are priced in consumption tiers, so a home running AC and dehumidifiers can push into more expensive blocks. Check the current residential table on ARESEP's tariff page for your specific distributor.
What this means in practice: If a closed home uses 900 kWh in a month to stay dry, simple math at the national average price lands near $170, before any higher-tier pricing. That is not a forecast. It is a way to see the line item clearly. Skipping that cost to save money is usually the more expensive choice, as the next section explains.
Cost 2: Roads, Rivers, and Getting Home
Guanacaste's road network is improving, but it is still rough by North American standards. A July 2026 report by Infobae citing LanammeUCR, the national roads laboratory, found that 25.5 percent of Guanacaste's national road network is gravel, the highest share of any province. On the local cantonal network, 50 to 70 percent of roads remain unpaved.
Rain turns that into a real cost. In September 2025, Guananoticias reported that Santa Cruz and Nicoya were the hardest-hit cantons after a single day of heavy rain. The Paraíso to Junquillal crossing, on the same stretch of coast as Playa Negra, closed when the river rose, and parts of Ostional and Nosara lost power, internet, and phone service.
The costs here are practical: a higher-clearance vehicle, faster tire and suspension wear, extra drive time, and the occasional day you simply stay home. Budget for all four.
Cost 3: Humidity and the Empty House Problem
Humidity is the green season cost owners underestimate most. The U.S. Environmental Protection Agency recommends keeping indoor humidity below 60 percent, ideally between 30 and 50 percent, and notes that a simple humidity meter costs $10 to $50.
On a tropical coast in October, a sealed house with the AC off will not stay below 60 percent on its own. The damage builds quietly: musty closets, spotted fabric, warped wood, and corroded electronics. The fix is cheap compared with the repair. Controlled air, airflow, and someone checking the house every week.
Cost 4: Vacancy and the Rental Calendar
If rental income helps carry your ownership costs, green season is where the math tightens. Short-term rental data from AirROI's Tamarindo market report shows February as the peak month for occupancy and September as the lowest.
Vacancy costs you twice. You lose booking revenue, and an empty house needs more care, not less. You have three levers for these months: monthly rates for remote workers, longer minimum stays, and owner visits timed for the quiet weeks. For a full breakdown of fees and net income, see our guide to Costa Rica vacation rental management fees and net income.
A Tale of Two Septembers
Consider two illustrative owners with similar four-bedroom homes near Playa Negra. Both fly home to Colorado from mid-August to late November.
Owner one turns off the AC to save on power, locks up, and asks a friend to "swing by if there's a storm." A river crossing closes for two days in September, so the friend never makes it. In December, the owner opens the door to a musty smell, mildew on closet walls, and swollen cabinet doors. The power savings are gone many times over, and the first two weeks of high season go to cleanup instead of guests.
Owner two sets the AC and dehumidifiers on a schedule, places humidity meters in each closet, and pays a caretaker for weekly inspections with photos. The power bill runs higher, and the caretaker adds a monthly cost. In December, the house is ready for the first booking on day one.
Owner two spent more in September. Owner one spent more overall.
The Green Season Owner Checklist: 8 Steps to Take Before May
- Confirm your electricity distributor and tariff. Pull a recent bill and compare it against the current residential table on ARESEP's site, so you know where the higher tiers start.
- Install humidity meters. Place one in each bedroom closet and one in the main living area. Your target is below 60 percent.
- Schedule your air. Set AC and dehumidifiers on timers or smart controls you can check remotely. Never leave a sealed home fully off for weeks.
- Protect your electronics. Add surge protectors to major appliances and a battery backup for your router and security cameras.
- Plan your access. Choose a higher-clearance or 4x4 vehicle, save local road reports, and follow one firm rule: never drive into a flooded river crossing.
- Hire weekly inspections. Ask for photos of closets, ceilings, and window seals, plus a written note after every major storm.
- Reprice your calendar. Set monthly rates for September and October and block owner weeks early.
- Build a green season reserve. Set aside funds for higher power use, vehicle wear, caretaking, and one surprise repair.
How Managed Co-Ownership Changes the Green Season Math
Much of the green season cost comes from carrying a home alone while you are not there. Shared, managed ownership spreads that load.
At Black Coast Estates, a one-eighth equity share includes a minimum of 42 days of use per year, scheduled through a snake-draft app. Estate management is handled by The Serena Company, which keeps homes watched, maintained, and ready between stays. That does not make green season free. Dues and operating costs still exist, and every structure should be reviewed with your advisers. What it changes is who is checking the closets in October. You can explore the setup on The Community page.
If you want to walk through a year of ownership month by month, including green season, you can book a private call with the Black Coast team.
Is Living in Guanacaste Year-Round Right for You?
Living in Guanacaste year-round rewards owners who plan for the whole calendar, not just February. Power is manageable. Roads take patience. Humidity punishes neglect. Vacancy calls for a different rental strategy. Handle those four lines on purpose, and green season becomes the quietest, greenest, most local stretch of the year.
For answers on ownership, scheduling, and management, visit our Questions page, or book a private call to talk through your plans.
About the author
[Author Name] is [role] at Black Coast Estates, with [X years] living in or working on the Guanacaste coast. [One line of real, first-hand green season experience, for example managing homes through the September rains.]
Frequently Asked Questions
What months are the rainy season in Guanacaste?
The rainy season in Guanacaste generally runs from May through November. September and October are usually the wettest months, and December through March is the dry season. A short, drier break called the veranillo often arrives in July and August, when trade winds strengthen and rainfall eases for a few weeks.
Does it rain all day during green season in Costa Rica?
Usually not. On Guanacaste's Pacific coast, most green season days start sunny, with rain arriving as afternoon or evening storms. Some days are overcast or drizzly, and strong systems can bring heavy rain for a day or more, especially in September and October, when rivers can rise and close local crossings.
How much is the electric bill for a home in Guanacaste?
It depends on home size and how much you run AC and dehumidifiers. Costa Rica's average residential price was about 85.9 colones per kWh, roughly $0.19, in December 2025, and ARESEP cut 2026 rates by 4.9 to 16.4 percent depending on the utility. Residential tariffs are tiered, so higher use can cost more per kWh.
Do you need a 4x4 to live in Guanacaste year-round?
It is strongly recommended. According to LanammeUCR figures reported in 2026, about a quarter of Guanacaste's national road network is gravel, and 50 to 70 percent of local cantonal roads are unpaved. A higher-clearance or 4x4 vehicle handles rainy season mud and potholes far better. Never drive into a flooded river crossing.
How do you prevent mold in a Costa Rica home during rainy season?
Keep indoor humidity below 60 percent, ideally 30 to 50 percent, as the U.S. EPA recommends. Run AC or dehumidifiers on a schedule even when the house is empty, place humidity meters in closets, keep air moving, and have someone inspect the home weekly. Fix leaks and wet materials quickly.
Is green season a slow time for vacation rentals in Guanacaste?
Yes. AirROI's short-term rental data for Tamarindo shows September as the lowest occupancy month and February as the highest. Common adjustments include monthly rates for remote workers, longer minimum stays, and planned owner visits during the quiet weeks, then protect peak season dates with stronger pricing.
